Having scales when mixing plaster is the most reliable method but if you don't have them you can gauge how much to add by looking out for islands of plaster forming on the surface of the water. …
Correct mixing of Fine Casting plaster for mould making and casting. Ratios are: 1 Litre cold water - 1.3kg dry plaster powder 2 Litres cold water - 2.6kg dry plaster powder 3 Litres cold water -…